Method for harvesting cochineal wax from cochineal insects grown on an artificial medium

ABSTRACT

A method for obtaining cochineal wax is provided which comprises (a) harvesting cochineal insects from an artificial medium inoculated with the insects; (b) extracting cochineal wax from the insects with a liquid medium; and (c) isolating cochineal wax from the liquid medium.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.61/507,188, filed Jul. 13, 2011, having the same title, and having thesame inventors, and which is incorporated herein by reference in itsentirety.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to naturally occurring waxes,and more particularly to systems and methods for harvesting wax fromcochineal insects which have been incubated on an artificial medium.

BACKGROUND OF THE DISCLOSURE

Carmine (also called cochineal) is a deep red, naturally occurring dyewhich has been used for thousands of years by populations in Central andNorth America. Despite the difficulty of producing carmine, the colorantis still in wide-spread demand. Carmine is an FDA approved additive, andis used to enhance the appearance of food, confections, pharmaceuticalsand cosmetics. In addition, its staining properties make it an excellentcontrasting agent for microbiological studies and cellular research.Carminic acid (see STRUCTURE I below), which is the dominantchromophoric ingredient in carmine, is naturally produced during thelife cycle of female insects of the genus Dactylopius, such as those ofthe species Dactylopius coccus (referred to herein as cochinealinsects).

Cochineal insects occur naturally as parasites on cacti of the genusOpuntia, with Opuntia ficus-indica being the most suitable host.Historically, cultivation of cochineal insects for large scale harvestwas initiated through careful inoculation of cacti with infected cactuspads or with pathogen-free females. Typically, in this approach, theinsects are introduced to the host via baskets known as Zapotec nests.After inoculation, the cochineal insects must be protected frompredators and from harmful weather conditions during their 3 monthgrowth cycle.

Carmine is then laboriously extracted from the tiny (about 0.2 inch or0.5 cm in length) female cochineal insects after the pads of theinoculated cacti are gathered. Approximately 155,000 insects arerequired to yield a single kg of carminic acid. The harvesting processis a labor and time intensive endeavor, and typically involves removingthe cochineal insects by hand from the infected cactus pads.

More recently, it has been discovered that cochineal insects can becultivated on an artificial medium. The details of this process may befound in commonly assigned U.S. 2011/0036295 (Merkle et al.), entitled“MEANS TO CULTURE COCHINEAL INSECTS IN AN ARTIFICIAL MEDIUM”, which wasfiled on Feb. 26, 2010, and which is incorporated herein by reference inits entirety. This approach has opened the door for widespreadlaboratory cultivation of cochineal insects.

SUMMARY OF THE DISCLOSURE

In one aspect, a method is provided for obtaining cochineal wax. Themethod comprises (a) harvesting cochineal insects from an artificialmedium inoculated with the insects; (b) extracting cochineal wax fromthe insects with a liquid medium; and (c) isolating cochineal wax fromthe liquid medium.

In another aspect, a method for obtaining cochineal wax is provided. Themethod comprises (a) inoculating an artificial medium with cochinealinsects; and (b) extracting cochineal wax from the insects with a liquidmedium.

In a further aspect, a method is provided for obtaining cochineal wax.The method comprises (a) inoculating an artificial medium with cochinealinsects; (b) pulverizing the inoculated medium; and (c) extractingcochineal wax from the pulverized medium.

In still another aspect, a composition of matter is provided whichcomprises an artificial medium inoculated with cochineal insects.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is flowchart for a process of recovering cochineal wax andcarminic acid from cochineal insects in accordance with an embodiment ofthe methodologies disclosed herein.

DETAILED DESCRIPTION

As noted above, the methodologies disclosed in U.S. 2011/0036295 (Merkleet al.) have opened the door for widespread laboratory cultivation ofcochineal insects. However, these methodologies have also been found tohave further benefits as well. In particular, with suitablemodification, these methodologies provide a convenient means by whichuseful products in addition to carmine may be recovered from cultivatedcochineal insects.

The presence of cochineal insects on its native host, prickly pear(Opuntia), is typically indicated by a white, cottony substance. Thissubstance, which has the appearance of mold or silk, is coccerin (alsocalled cochineal wax), a waxy mixture secreted by the insects.Chemically, cochineal wax is known to contain predominantly coccericacid (coccerylic acid, C₃₁H₆₂O₃, mp 92-93° C.) and cocceryl alcohol(C₃₀H₆₂O₂, mp 101-104° C. or (C₃₀H₆₀(OH)₂). Cochineal wax providesprotection for the insects and their colonies. Moreover, developinginsects use strands of the material to catch the wind and sail to newlocations to form new colonies.

While the chemical composition of cochineal wax has been known for sometime, it has heretofore existed as little more than an academiccuriosity. Traditional cochineal insect farming, which is an establishedpractice going back many hundreds of years, has focused on thecollection of female insects, since they are the primary source ofcarmine Much of the cochineal wax content produced by cochineal insectsis not collected. This includes cochineal wax present in secretions onthe infested host plant and in cocoons produced by the insects, as wellas cochineal wax present in the bodies of nymphs and male insects.

Although cochineal wax is also present in the bodies of female insectsand is incidentally collected as a result in conventional cochinealinsect farming, this content is typically discarded during subsequentprocessing. Thus, defatting solvents, such as methylene chloride, aretypically used to clear the wax from cochineal preparations prior toprocessing and conversion of carminic acid to carmine Hence, cochinealwax has heretofore been treated as an undesirable byproduct in theproduction of carmine Undoubtedly, this is due in part to the relativelysmall amounts of cochineal wax afforded by traditional cochineal insectharvesting.

However, it has now been found that, with suitable modification, themethodologies described in U.S. 2011/0036295 (Merkle et al.) are capableof yielding much larger amounts of cochineal wax than would be affordedby traditional cochineal farming techniques. Without wishing to be boundby theory, this result is believed to be due to the fact that all of thesources of cochineal wax associated with cochineal insects (includingboth male and female insects and nymphs, cocoons, and secretions) may bereadily subjected to the extraction process used in this reference torecover carminic acid from the insects, thus resulting in significantlygreater portions of cochineal wax in the extract. Consequently, with theaddition to this process of a suitable wax extraction or wax isolationtechnique, it is possible to economically recover cochineal wax as avaluable byproduct of this process.

FIG. 1 illustrates a first particular, non-limiting embodiment of amethod for harvesting cochineal wax in accordance with the teachingsherein. The particular embodiment illustrated is implemented as part ofa process for growing cochineal insects on an artificial medium forextraction of carminic acid therefrom, it being understood that thesystems and methodologies described herein are also applicable toharvesting wax from cochineal insects grown in the wild, either inconjunction with, or apart from, a carminic acid extraction process.

With reference to FIG. 1, a suitable medium is inoculated 101 withcochineal insects. The insects are then incubated 103, and aresubsequently isolated 105 from the medium when they have attained asuitable age. The isolated insects are then dried and pulverized 107(this step may be omitted in some embodiments), after which cochinealwax 109, and then carminic acid 111, are extracted from the insects.Suitable techniques for wax extraction in the context of this embodimentare described below.

The importance of naturally-derived waxes in coatings, food, lighting,fuels, art supplies, polishes, and other such products cannot beoverstated. Given the similarities of the coccerin components to waxesin widespread/ubiquitous use, and its higher melting points (mp) thansome animal and vegetable waxes and fats, the efficient and effectiveproduction of purified coccerin and its components has the potential tosignificantly augment or even replace waxes currently in use.

Cocceric acid, the hydroxylated acid of the form C_(n)H_(2n)O₃, is inthe same series as lanolin or lanopalmitic acid (C₁₆H₃₂O₃, mp 87-88°C.), the useful and valuable wax which is isolated from sheep's wool.Cocceryl alcohol (cocceryl coccerate, C₃₀H₆₂O₂, mp 101-104° C.) is analcohol of the glycolic series C_(n)H2_(n+2)0₂, and is a branched ester(mp 103.5-103.8° C.) present in carnauba wax, a valuable hard waxisolated from the Brazilian palm, Copernicia prunifera. Myrisyl alcohol,a component of beeswax, is also present in small amounts in cochinealwax. Beeswax is used for polishing, candles, skin care products, andfoodstuffs. It will thus be appreciated that Coccerin and its componentshave the potential to be valuable to the pharmaceutical and foodindustries, in skin care products, as coatings and additives forcoatings on paper and other substrates, for polishes and surface waxes,and as art supplies (such as, for example, Chinese wax (insect wax,ceryl cerotate, mp 82.5° C., derived from Coccus ceriferus)).

Cochineal wax may be readily extracted from culture-grown insects. In apreferred embodiment of the extraction process, the growth medium,either fresh or dried, is scraped of all cochineal material, includingwax, cocoons, nymphs, pregnant females, and the like. This collected andcombined material is then be crushed and boiled in hot distilled water.This dark red preparation is preferably cooled below 60° C. so that thewax, with a melting point of ˜100-102° C., solidifies and floats to thetop, allowing for easy removal. The hot water extract may then beconcentrated by evaporation, and the resulting flat, dark red crystalsof carminic acid may be converted to carmine by published methods.Advantageously, this procedure reduces or eliminates the need fororganic solvents.

While the foregoing embodiment is the preferred methodology forextracting cochineal wax from culture-grown insects, other methodologiesmay be utilized as well. Preferably, these methodologies involveextracting the cochineal wax with a liquid medium which is heated to afirst temperature T₁, wherein T₁>Tmp_(wax), and wherein Tmp_(wax), isthe melting point of cochineal wax. The cochineal wax is then preferablyextracted from the liquid medium by cooling the liquid medium to asecond temperature T₂, wherein T₂<Tmp_(wax). Preferably, T₁>102° C. andmore preferably, T₁>110° C. Preferably, T₂<60° C. and more preferably,T₂<40° C.

Of course, it will be appreciated that various modifications may be madeto the foregoing process. For example, in some embodiments, theinoculated growth medium may be crushed or pulverized to form a powderor other particulate mass from which cochineal wax and carminic acid maybe readily extracted.

It will also be appreciated that the systems and methods describedherein for obtaining cochineal wax are not limited to use with cochinealinsects grown on an artificial medium, though such a use is preferred.Hence, for example, these systems and methodologies may be applied tothe production of cochineal wax from insects grown in the wild (e.g., onprickly pear farms).

It will further be appreciated that the cochineal insects and the mediumthey are grown on (which may be natural or artificial) may or may not bedried prior to pulverization or wax extraction, assuming that thesesteps are utilized in the first place. Moreover, while wax extractionwith hot H₂O is preferred, one skilled in the art will appreciate thatvarious solvent systems may be utilized in place of, or in addition to,hot H₂O.

Finally, it will be appreciated that various additional steps may beperformed in the processes described herein. By way of example, therecovered wax may be subjected to various purification processesincluding, without limitation, various filtration or distillationtechniques.

The above description of the present invention is illustrative, and isnot intended to be limiting. It will thus be appreciated that variousadditions, substitutions and modifications may be made to the abovedescribed embodiments without departing from the scope of the presentinvention. Accordingly, the scope of the present invention should beconstrued in reference to the appended claims.

1. A method for obtaining cochineal wax, comprising: providing anartificial medium inoculated with cochineal insects; extractingcochineal wax from the cochineal insects with a liquid medium; andisolating the cochineal wax from the liquid medium.
 2. The method ofclaim 1, wherein extracting cochineal wax from the cochineal insectswith a liquid medium involves heating the liquid medium to a firsttemperature T₁, wherein T₁>Tmp_(wax), and wherein Tmp_(wax) is themelting point of cochineal wax.
 3. The method of claim 2, whereinisolating the cochineal wax from the liquid medium involves cooling theliquid medium to a second temperature T₂, wherein T₂<Tmp_(wax).
 4. Themethod of claim 3, wherein T₁>102° C.
 5. The method of claim 3, whereinT₁>110° C.
 6. The method of claim 3, wherein T₂<60° C.
 7. The method ofclaim 1, wherein the liquid medium is an aqueous medium.
 8. The methodof claim 6, wherein the liquid medium is an aqueous medium, wherein thewax floats to the top of the liquid medium when the liquid medium iscooled to the second temperature, and wherein isolating cochineal waxfrom the liquid medium further involves collecting the wax from thesurface of the liquid medium.
 9. The method of claim 1, wherein thecochineal insects are pulverized after they are harvested and before thecochineal wax is extracted.
 10. The method of claim 1, furthercomprising: harvesting the cochineal insects from the artificial mediumprior to extracting cochineal wax from the cochineal insects; whereinharvesting the cochineal insects includes removing both male and femaleinsects from the artificial medium.
 11. The method of claim 1, furthercomprising: harvesting the cochineal insects from the artificial mediumprior to extracting cochineal wax from the cochineal insects; whereinharvesting the cochineal insects includes removing cochineal wax fromthe artificial medium.
 12. The method of claim 1, further comprising:harvesting the cochineal insects from the artificial medium prior toextracting cochineal wax from the cochineal insects; wherein harvestingthe cochineal insects includes harvesting the cocoons of cochinealinsects from the artificial medium.
 13. The method of claim 1, furthercomprising: harvesting the cochineal insects from the artificial mediumprior to extracting cochineal wax from the cochineal insects; whereinharvesting cochineal insects from an artificial medium includesharvesting cochineal nymphs from the artificial medium.
 14. The methodof claim 1, wherein the artificial medium comprises a plant additive anda polymeric material.
 15. The method of claim 14, wherein the plantadditive is a cactus additive.
 16. The method of claim 15, wherein thecactus additive is derived from the genus Opuntia.
 17. The method ofclaim 1, further comprising: drying the cochineal insects prior toharvesting them; wherein the cochineal insects are dried to about 20% toabout 40% of their original body weight.
 18. The method of claim 1,wherein harvesting cochineal insects from the inoculated mediumincludes: drying the inoculated medium; and pulverizing the dried mediumto generate a particulate mass.
 19. The method of claim 18, wherein theparticulate mass contains cochineal wax content, and wherein thecochineal wax content is chemically extracted from the particulate mass.20. The method of claim 19, wherein the particulate mass containscochineal dye content, and wherein the cochineal dye content is alsochemically extracted from the particulate mass.
 21. The method of claim20, wherein a mixture of the cochineal dye content and the cochineal waxcontent is chemically extracted from the particulate mass, and furthercomprising isolating the cochineal wax content from the mixture.
 22. Amethod for obtaining cochineal wax, comprising: inoculating anartificial medium with cochineal insects; and extracting cochineal waxfrom the insects with a liquid medium.
 23. The method of claim 22,further comprising: isolating cochineal wax from the liquid medium. 24.The method of claim 22, further comprising: grinding the inoculatedmedium to form a particulate mass.
 25. The method of claim 24, whereinextracting cochineal wax from the insects with a liquid medium involvesextracting cochineal wax from the particulate mass.
 26. The method ofclaim 24, wherein the particulate mass is a powder.
 27. A method forobtaining cochineal wax, comprising: inoculating an artificial mediumwith cochineal insects; pulverizing the inoculated medium; andextracting cochineal wax from the pulverized medium.